To date we have generated mice with Gq/11-alpha deficiency in the paraventricular nucleus of the hypothalamus (PVN) using Sim1-cre transgenic mice. Preliminary findings show that these mice are underweight in the first month of life but then do develop severe obesity. However when the mice are housed individually they do not gain weight, suggesting that environment may imppact on the phenotype. Studies are underway to determine to what extent this is due to excess food intake vs. reduced energy expenditure.